1. Field of the Invention
The present invention relates to an image reading device and a method for manufacturing the same.
2. Description of the Related Art
In an apparatus such as a fax machine, a copy machine, or a scanner, an image reading device for reading an original manuscript is installed. FIG. 18 shows an example of the image reading device (for example, referring to Patent Document 1). The image reading device X shown in FIG. 18 includes a case 91, a linear light source 92, a lens array 93, a substrate 94, and a receiving element 95 carried on the substrate 94. The case 91 includes a light source accommodating portion 911 for accommodating the linear light source 92 and a lens accommodating portion 912 for accommodating the lens array 93. The linear light source 92 includes a light guiding body 921 extending long in a main scanning direction and a white case 922 for accommodating the light guiding body 921. An opening is formed on a side of the white case 922, so as to expose a light emitting portion 921a of the light guiding body 921. Furthermore, the linear light source 92 includes a light source unit (not shown) fixed on an end portion of the white case 922 in the main scanning direction. A Light Emitting Diode (LED) is mounted into the light source unit to provide light for the light guiding body 921. The light from the light source unit goes forward in the light guiding body 921 in the main scanning direction, and a part of the light is emitted from the light emitting portion 921a. A glass cover 96 shown in FIG. 18 is disposed on the apparatus in which the image reading device X is installed. In the image reading device X, the linear light source 92 is used to illuminate the original manuscript G, and the lens array 93 is used to guide reflected light into the light receiving element 95, so as to read the original manuscript G.
The image reading device X is formed so that when the linear light source 92 is accurately disposed in the light source accommodating portion 911 of the case 91, the original manuscript G is well illuminated. For example, if the linear light source 92 is installed in a state of inclining toward the light source accommodating portion 911, the original manuscript G is non-uniformly illuminated, and the quality of the read image can be deteriorated. Moreover, if deviation occurs in the position of the lens array 93 in the lens accommodating portion 912, light from the original manuscript G can not be smoothly received by the light receiving element 95. Therefore, an adhesive, for example, needs to be used to fix the linear light source 92 and the lens array 93 in a specified position. If silicone resin hardened at a normal temperature is used as the adhesive, it takes a long time to harden. In this case, the image reading device X needs to be held still for a long time, so that the positions of the linear light source 92 and the lens array 93 do not deviate.
Another issue with the image reading device X is that faster assembly is required during manufacture. The time required fixing the linear light source 92 and the lens array 93 to harden the silicone resin hinders efficient assembly.
Patent Document 1: Japanese Patent Laid-Open Publication No. 2007-27137